The present invention relates generally to medical instruments that are utilized for obtaining tissue samples from patients. More particularly, the present invention is directed to remote tissue harvesting and collection apparatus and to associated methods of use that are particularly well suited for operation in circumstances where conditions may expose personnel performing the tissue collection to personal hazard from environmental factors, including X-rays.
In the course of examining patients, physicians may at times come upon unusual or suspect masses of tissue at various locations throughout the patient""s body. For example, these suspect masses of tissue may be located on the body surface of the patient, as well as internally or within particular body organs or structures. Customary medical methods for investigating these suspect masses of tissue include visual inspection, often with aid of magnifying devices, and tactile inspection with the fingers, especially where the suspect mass is internalized within the patient""s body. Additional methods for investigating internalized, as well as surface tissue masses, include visualization methods such as X-ray and magnetic resonance imaging (MRI).
Often these methods, either alone or in combination, may not provide enough detailed information about the suspect tissue mass under investigation to allow a physician to diagnose or treat the medical condition associated with the tissue mass. As a result, it is not uncommon for a physician to order a biopsy procedure to be performed on the patient so that the suspect tissues or cells are removed from the patient and then examined in greater detail. The sample of suspect tissue may be obtained by several commonly practiced methods using a variety of medical instruments and tools. These methods include obtaining a tissue plug from the patient""s body with a cannula, aspiration of suspect tissue through a needle, swabbing the suspect tissue with a sponge, scraping suspect tissue with a curette, boring into suspect bone tissue with a trepan, or excision of the suspect tissue with a forceps or electric snare, for example. Often the biopsy tissue sample is taken from the edge of the suspect area so as to obtain a sample that contains both healthy and diseased tissue for a more complete tissue comparison and analysis.
The collecting of such tissue samples for biopsy is a standard step in the diagnosis of malignant and benign tumors, as well as other suspect tissues. These tissue biopsies also provide a wide range of other types of diagnostic information, particularly in connection with organs such as the liver or pancreas. By utilizing these methods, a doctor is better able to identify and diagnose a patient and to prescribe the appropriate methods of treatment.
When areas to be biopsied are extracorporeal, or located outside of the patient""s body, the initial placement of the prior art medical devices used to extract the samples from the suspect tissues of interest are usually done by hand under direct visualization by the attending medical personnel. However, when the mass of suspect tissue is situated inside of the patient""s body, the use of internal visualizing techniques becomes necessary. Without the aid of such techniques, medical personnel conducting the biopsy operation are unable to see the location of internal target areas or, of equal importance, the internal structures that may lie between the point of insertion of the biopsy instruments and their target areas. Without the aid of such prior art enhanced visualization techniques, the medical personnel must insert and guide the biopsy instruments blindly, running the potential risk of impacting healthy tissue located along the intended pathway of the biopsy instrument. Moreover, without such prior art visual aids, it may be possible for the medical personnel to miss the target tissue area entirely, or to over-penetrate the target area and sample tissue outside the target tissue area.
More recently, in an attempt to overcome such visualization obstacles, physicians have been performing biopsies utilizing relatively new methods of enhanced X-ray visualization known as Computed Tomography or xe2x80x9cCTxe2x80x9d. CT allows physicians to obtain a two-dimensional plane view of a cross-section of any part of the patient or targeted internal tissues or organs by combining conventional X-ray technology with modern computers and visual displays. For example, in a CT scan, multiple X-rays are taken as the CT X-ray revolves around the patient placed within the scanning machine. A computer then calculates the amount of X-ray penetration through the specific planes of the body parts examined, and gives each a numeric value known as a xe2x80x9cdensity coefficientxe2x80x9d. This information is fed into a computer, which translates the density coefficient values into different shades of gray displayed on a television monitor. These displayed images can be presented to the physicians as photographs in a series of two-dimensional photographic images displaying cross-sections of the target areas under examination. When taken as part of a biopsy procedure, these images can be used by the attending medical personnel to visualize both the target areas from which the biopsy samples are to be taken as well as the relative position the biopsy instruments within the patient and the progression of the biopsy instruments along their intended pathways to the suspect masses of tissue at the target areas.
Though successful at helping to direct biopsy instruments, a remaining disadvantage of CT scanning is the fact that the medical personnel performing the biopsy procedures must be mindful of their personal, continued, multiple exposure to the X-ray beam utilized during the CT scanning operations. Failure to do so can lead to the resultant possibility of personal overexposure to X-ray radiation. Overexposure is not an issue to patients due to their relatively brief X-ray exposure. Conversely, medical personnel conducting hundreds of biopsies per year run the risk of significant, cumulative overexposure to X-rays and the subsequent risks to their own health. As a result, this potential for X-ray overexposure requires that any attending medical personnel exit the scan room when the X-ray scanning procedure is taking place. Then, at a later time they can evaluate the CT scan of the area of interest on the patient, analyze the resulting CT images and mark points and decide angles of insertion for biopsy apparatus. Subsequently, in order to advance the biopsy apparatus by moving the tissue sampling instruments deeper into the body, a meticulously slow process follows, consisting of repetitive exits from the scanning room, repetitive CT scans and repetitive image analyses. In between CT scans, the medical personnel advance and adjust the position of the tissue sampling instruments (a cannula, for example), and then scan for the resultant changes in cannula position illustrated by the subsequent CT scans. By using this xe2x80x9cstill-framexe2x80x9d technique, the progress of the cannula advancing toward the target area is monitored and directed. Though successful, this xe2x80x9cstill-framexe2x80x9d biopsy visualization methodology is very time consuming and awkward for both patients and attending medical personnel. It is also very expensive and can lead to cost-conscious restrictions on its availability and use.
In view of these drawbacks, continued prior art research has developed an additional method to help medical personnel visualize the interior of biopsy patients in xe2x80x9creal-timexe2x80x9d as opposed to xe2x80x9cstill-framexe2x80x9d imaging. xe2x80x9cReal-timexe2x80x9d imaging enables the medical personnel, with what are essentially xe2x80x9clivexe2x80x9d images or, in other words, to continuously monitor the target areas of interest. This later method is referred to in the art as xe2x80x9creal-time CT fluoroscopyxe2x80x9d. Utilizing real-time CT fluoroscopy affords medical personnel the ability to generate faster two-dimensional cross-sectional image constructions allowing the target areas to be displayed in xe2x80x9creal-timexe2x80x9d. Medical personnel utilizing this prior art method do not leave the room while the patient is undergoing X-ray scanning. This results in the medical personnel remaining near the X-ray field to manually guide the biopsy instrument""s progression to the target tissue in xe2x80x9creal-timexe2x80x9d using the xe2x80x9creal-timexe2x80x9d images. While this method provides a continuous, internal view of the patient""s target area, the exposure of attending medical personnel to continuous X-rays and the continuing possibility of their personal overexposure to X-rays remains a major concern and limitation on the use of such techniques.
Prior art attempts at reducing radiation exposure and procedure times for medical personnel performing biopsies under xe2x80x9creal-timexe2x80x9d visualization have relied on simple mechanical solutions akin to removing the medical personnel from the scanning environment. Basically, these techniques involve the medical personnel performing the xe2x80x9creal-timexe2x80x9d CT fluoroscopy biopsy procedures utilizing simple, passive tools to hold the biopsy instruments. Utilizing a tool such as a set of simple plastic forceps or towel clamps places the hands of medical personnel at approximately 10 cm further away from the X-ray beam. Though effective at reducing X-ray exposure, as one skilled in the art will appreciate, such extending forceps or clamps also position the hands of medical personnel out of direct contact with the patient and biopsy site. Further, such tools also position the biopsy apparatus out of direct contact and control of the attending medical personnel performing the biopsies. The resultant lack of feel, control and stability during the biopsy procedure, combined with the amount of X-ray radiation exposure (3.05 mSV for a 30-second scan at a distance of 10 cm, for example) still associated with such procedures continues to be a source of concern. Additionally, it is extremely difficult, if not impossible, to take biopsy samples from hard tissues such as bone or cirrhotic livers utilizing such forceps or clamp methodologies.
Accordingly, one of the objects of the present invention is to provide remote tissue biopsy apparatuses and associated methodologies that will allow for the accurate and rapid control and positioning of biopsy instruments and for the associated accurate and rapid harvesting of biopsy samples.
An additional object of the present invention is to provide methods and associated apparatuses by which biopsies can be performed under remote control thereby reducing the biopsy conducting medical personnel exposure to hostile environments which may include X-rays, radiation, toxins, pathogens and other hazards.
These and other objects are achieved by the methods and associated remote tissue biopsy apparatus of the present invention which accurately and rapidly obtain biopsy tissue samples, even in environments that are hostile to medical personnel. In accordance with the broad teachings of the present invention, exemplary remote tissue biopsy apparatus and methods are provided which utilize remotely controllable tissue harvesting and collection heads. These collection heads are provided with a reciprocating driving conveyor having attached a tissue collection cannula. A releasable cannula retaining carrier can be used to attach the tissue collection cannula to the reciprocating driving conveyor. It should be noted that while the present invention will be discussed in the context of biopsy procedures, those skilled in the art will appreciate that the present invention is readily applicable to other tissue harvesting and collection procedures outside of biopsies.
In further accordance with the broad structural aspects and teachings of the present invention, positioning of the remotely controllable tissue harvesting and collection head is further achieved by placing the remotely controllable tissue harvesting and collection head in a mounting fixture for these purposes. An exemplary mounting fixture, for example, may be a component of a handheld unit or of a track mounted robotic apparatus. Further, the remotely controllable tissue harvesting and collection head of the present invention can be connected to the mounting fixture to be spherically pivotable. This provides the apparatus of the present invention additional freedom of motion to allow easier and more precise positioning of the remote controllable tissue harvesting and collection head.
If desired to provide additional structural stabilization to the tissue collection cannula utilized in the present invention, the remote tissue biopsy apparatus of the present invention can include, disposed distally and in axial alignment to the reciprocating driving conveyor, a tissue collection cannula guide. When desired, by providing this tissue collection cannula guide, the present invention further minimizes the amount of flexing and misalignment that may occur between the respective ends of a tissue collection cannula as force is applied to drive the distal end of the tissue collection cannula into the patient undergoing the biopsy procedure.
The remote tissue biopsy apparatus of the present invention can be provided with a remote control that is operatively connected to the remotely controllable tissue harvesting and collection head. This remote control includes an operatively attached tissue harvesting and collection head control mechanism and a user input interface. This enables medical personnel performing a biopsy to actuate and operate the remotely controllable tissue harvesting and collection head from a distance, outside of a X-ray scanning field, for example. In accordance with the teachings of the present invention the tissue harvesting and collection head control mechanism can be, for example, mechanical, pneumatic, electrical or hydraulic mechanisms. These mechanisms can actuate, for example, levers, belts, chains, pistons, cylinders or solenoids that operatively connect the user input interface to the remotely controllable tissue harvesting and collection head.
In an exemplary handheld embodiment of the present invention, the user input interface is mechanical, structurally simple and disposed at a handle portion of the apparatus provided in accordance with the teachings of the present invention.
To collect or harvest suspect tissue of interest in accordance with the teachings of the present invention, the tissue harvesting and collection head is maneuvered to a predetermined location on the patient. This location can be predetermined and previously marked by medical personnel based on visualization, palpation or images from earlier scans of the target tissue. Then, while the CT fluoroscope is turned on and a cross-sectional image is constructed of the patient""s internal target tissue area, the medical personnel evaluate this visual image and position the remote tissue biopsy apparatus accordingly. This is accomplished manually if the embodiment of the present invention employed is handheld, or mechanically if an embodiment of the present invention is robotic. The medical personnel are then able to actuate and guide the remotely controllable tissue harvesting and collection head to the target tissue to be biopsied by utilizing the user interface of the remote tissue biopsy apparatus while continuously monitoring the images constructed by the scanner. This remote tissue biopsy apparatus and technique enables the medical personnel to adjust, in xe2x80x9creal-timexe2x80x9d, the aim and progression of the tissue collecting instruments toward the target areas.
Moreover, as will be appreciated by those skilled in the art, the exemplary remote tissue biopsy apparatus of the present invention is lightweight and can be handheld or robotic. An exemplary handheld remote tissue biopsy apparatus of the present invention has a xe2x80x9cgun-likexe2x80x9d appearance, in that the remotely controllable tissue harvesting and collection head can be disposed distally from a xe2x80x9cpistol-gripxe2x80x9d member. The pistol grip contains the user input interface that is operatively linked to the remote control mechanism, in this embodiment, disposed within the handheld remote tissue biopsy apparatus.
Alternatively, at least a portion of exemplary remote tissue biopsy apparatus of the present invention can be manufactured as a disposable unit and, as such, can be constructed of appropriately robust yet inexpensive materials. Whether disposable or not, a handheld remote tissue biopsy apparatus may be proportioned so as to fit within confined areas, such as a CT apparatus or otherwise restrictive areas. Additionally, within the scope and teachings of the present invention, the handheld remote tissue biopsy apparatus are of sufficient extending length to distance the medical personnel for protection from X-rays associated with CT procedures or from other hazards such as heat, toxins, energy fields or biohazards. Alternatively, within the teachings of the present invention, a handheld remote tissue biopsy apparatus also can provide shielding, such as lead, incorporated into the design and materials utilized in the construction of the handheld remote tissue biopsy apparatus in order to further minimize the user""s exposure to radiation or other detrimental elements.
In further accordance with the novel structural aspects of the present invention, the mounting fixture can be part of a remote control, robotic apparatus. Such robotic apparatus of the present invention can be similar to robots found in modern automated assembly lines. Such exemplary robotic apparatus of the present invention can mount the tissue harvesting and collection head on robotic positioning and extension arms disposed on a track. This robotic positioning and extension arm allows accurate three-dimensional remotely controlled positioning of the tissue harvesting and collection head through points in the x, y, and z planes.
The remotely controllable robotic apparatus of the present invention allows medical personnel to obtain biopsy samples from both hard and soft tissues with precision, control and safety, without any direct physical contact between the medical personnel conducting the biopsy procedures and the patients. This apparatus and methods of the present invention are equally adaptable to other medical devices, such as CT fluoroscopes or even to portable platforms for ease of transport and for use in remote locations.
The following non-limiting detailed description and drawings, which illustrate, by way of example, the principles of the present invention, will provide additional enabling disclosure and examples and will make apparent additional features and advantages of the present invention to those skilled in the art.